11  Infrared image adjustment

11.1  General

An infrared image can be adjusted automatically or manually.
In automatic mode, the camera continuously adjusts the level and span for the best image presentation, using one of the following color distribution methods:
  • Histogram: The colors are distributed based on the thermal content of the image.
  • Linear: The colors are distributed evenly from the lowest to the highest temperature.
The color distribution method for the automatic mode is configured by a setting. Select icon (Settings) > Device settings > User interface options > Auto adjustment method.
By using the Auto adjustment region feature it is possible to select an area of the image, and then have the colorization of the image adjusted based on the temperatures within that selected area. For more information, see section 11.3 Auto adjustment region .
In manual mode, you can adjust the temperature scale to values close to the temperature of a specific object in the image. This mode lets you center on the temperatures around the background of the gas, to make the gas appear more clearly. When measuring temperatures, manual mode will make it possible to detect anomalies and smaller temperature differences in the part of the image of interest. In manual mode, the colors are distributed evenly from the lowest to the highest temperature (linear color distribution).
In manual mode, you can adjust the image by touching the screen or by using the navigation pad. For more information, see sections 11.4 Manual adjustment by touching the screen and 11.5 Manual adjustment by using the navigation pad .
  • In live mode, touch the soft button icon to switch between automatic and manual image adjustment modes.
  • In preview/edit mode, manual image adjustment mode is active.

11.2  Example

Here are two infrared images of an isolator in a power line. To make it easier to analyze the temperature variations in the isolator, the temperature scale in the right image has been changed to values close to the temperature of the isolator.
Graphic
Automatic
Graphic
Manual

11.3  Auto adjustment region

When you auto-adjust a thermal image, you adjust it for the best image brightness and contrast. This means that the color information is distributed over the existing temperatures of the image.
In some situations, the image may contain very hot or very cold areas outside your area of interest. In such cases you might want to exclude those areas and use the color information only for the temperatures in your area of interest. You can do so by selecting a smaller auto adjustment region.
Select the auto adjustment region under icon (Settings) > Device settings > User interface options > Auto adjustment region.

11.4  Manual adjustment by touching the screen

11.4.1  General

The touch functionality for manual image adjustments is enabled/disabled by a setting. Select icon (Settings) > Device settings > User interface options > Manual adjustment using touch > On/Off.
When manual image adjustment mode is active, an adjustment wheel is displayed to the right of the temperature scale. (Applicable when the manual adjustment by touch functionality is enabled.)
Graphic

Figure 11.1  Manual adjustment mode active

11.4.2  Procedure

1

In live mode, touch the soft button icon to enter manual image adjustment mode.

2

To simultaneously change the temperature scale minimum and maximum limits, place your finger on the screen and move it up/down.

3

To change the minimum limit or the maximum limit, do the following:

  1. Touch the maximum or minimum temperature that you want to change.
  2. Place your finger on the screen and move it up/down to change the value of the highlighted temperature.

11.4.3  Auto-adjusting the image in manual mode

In manual image adjustment mode, you can auto-adjust the image by touching the screen. The image will be auto-adjusted based on the thermal content of the area around the touched point. The top and bottom levels in the temperature scale will be set to the maximum and minimum temperatures in that area. By using the color information only for the relevant temperatures, you will get more details in your area of interest.
Graphic

11.4.4  Locking the touch screen

When you have adjusted the image to levels that allow you to study your area of interest, you can lock the touch screen to prevent further unintentional adjustments.
To lock the screen, touch the icon icon to the left of the temperature scale.
To unlock the screen, touch the icon icon to the left of the temperature scale.

11.5  Manual adjustment by using the navigation pad

11.5.1  Manual adjustment modes

There are two different settings for the manual adjustment mode (applicable for the navigation pad only):
  • Level, Span: With this setting, you can manually adjust the level and span by using the navigation pad.
  • Level, Max, Min: With this setting, you can manually adjust the level by using the navigation pad. You can also change the upper and lower temperatures individually.
Select the type of manual image adjustment mode under icon (Settings) > Device settings > User interface options > Manual adjustment mode.

11.5.2  Manual adjustment in Level, Span mode

1

In live mode, touch the soft button icon to enter manual image adjustment mode.

2

Push the navigation pad up/down to increase/decrease the level.

3

Push the navigation pad left/right to increase/decrease the span.

11.5.3  Manual adjustment in Level, Max, Min mode

1

In live mode, touch the soft button icon to enter manual image adjustment mode.

2

To simultaneously change the temperature scale minimum and maximum limits, push the navigation pad up/down.

3

To change the minimum limit or the maximum limit, do the following:

  • Push the navigation pad left/right to select (highlight) the maximum or minimum temperature.
  • Push the navigation pad up/down to change the value of the highlighted temperature.